Appeal No. 2002-0510 Page 28
Application No. 09/139,309
Turning to the prior art, although Downing discloses "a stack of: exemplary disc-
like polycrystalline semiconductive resistive devices which in this case are chosen to be
silicon carbide varistors," col. 2, ll. 64-68, the examiner fails to show that the varistors
differ in their percentage loadings of conductive or semiconductive particles. Similarly,
although Slepian discloses that "[a] plurality of plates 1 of high-resistance material,
preferably but not necessarily containing graphite, carborundum and kaolin, are placed
in superposed relation as shown in Fig. 1," p. 2, ll. 11-15, the examiner fails to show
that the plates differ in their percentage loadings of conductive or semiconductive
particles. For its part, although Hyatt discloses a composition featuring a percentage
loading of at least about 55% by volume of conductive or semiconductive particles, the
examiner fails to show that the reference teaches using different loadings in different
layers of a device. In summary, we are persuaded that the fairest reading of the
references is to use the same loading in different layers of a device.
Furthermore, the examiner fails to allege, let alone show, that the addition of
Beck cures the aforementioned deficiency of Downing, Slepian, and Hyatt. Absent a
teaching or suggestion of a first layer and a second layer differ in their percentage
loadings of conductive or semiconductive particles, the examiner fails to present a
prima facie case of obviousness. Therefore, we reverse the obviousness rejections of
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